We had the Tent, and Forest caterpillars here in CNY for the last 2 yrs. They hit us hard, stripped all the hard maples & oaks both yrs. The forest caterpillar is the one that does most the damage. They're not the ones that make the tents. I used SEVIN spray to kill the bastards all around my house. It works well. Far as protecting your tree's soon as show up, wrap plastic wrap around them a few feet up. Then take some vaseline, and wipe it onto the plastic wrap. They won't crawl up past the sticky vaseline.
They have been moving southward for the past 4-5 yrs. They started northern NY, possibly Canada, and have moved south. They're in Southern NY, and PA now. You will have to deal with them for 2 seasons. So do all you can to protect any tree's you consider valuable. They can kill tree's from consecutives yrs of defoliating them. The maples & oaks will releaf, but it takes alot of nutrients from the tree, making it suspectable to other environmental conditions, and diseases.
The two are easily identifiable. The tent variety has a solid strip down its back. These I wouldn't be too concerned about, they do minor tree damage. The Forest has white dots down its back. They can devour a full size tree in just a few days. You'll hear their droppings hitting the ground so much it sounds like rain! They also will web down from above like a spider. They are terrible, and I feel for all of you on dealing with it.

Matt/PA the pic you posted of a mature Tent Caterpillar is actually the mature Forest Caterpillar variety. The tent variety is similar to that, but with a solid white stripe.

Here's a link w/pics & info on them via NYSDEC websight.
www.dec.ny.gov/animals/7111.html